Making a self-boot game from non

[GP02A]

ok here one question I dont understands from those posts about making self boot games. If I already have a self-boot game on cd and I want to make another copy. I have to extract it first and than use CDRWIN to record. But than why we cant use CDRWIN to make the a self boot game from a cdi-image. and why after extraction we use CDRWIN not DJ2??????